Sheet metal nibbling tool



June 2, 1959 l. .1.'YERMlsH SHEET METAL NIBBLING TOOL (FOR CORRUGATEDSHEET METAL) 3 Sheets-Sheet l Original Filed Oct. 5, 1956 INVENroR5R/TER Yam/:15H

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SHEET METAL NIBBLING TOOL (FOR CORRUGATED SHEET; METAL) Original FiledlOct. 5. 1956 .A 3 Sheets-Sheet 2 INVENTOR.

ISRAEL o- YEEMISH IMM HTTORll/EY June 2, 1959 l. J'. YERMlsH 2,888,744

SHEET METAL NIBBLING TOOL (FOR CORRUGATED SHEET METAL) Original FiledOct. 5, 1956 3 Sheets-Sheet 3 wg. A/0

H4' [lo] 23 L mmm 4 28 f6 m 3Ommmmn l 29 234g f6 @m48 3o 53 INVENTOR. v)SRI-TEL \\-\ERM|SH n T TORNEY Unite States Patent O SHEET METALNIBBLING TOOL (FOR CORRUGATED SHEET METAL) Israel J. Yermish,Philadelphia, Pa., assignor to Fenway Machine Company, Inc.,Philadelphia, Pa., a corporation of Pennsylvania Continuation ofapplication Serial No. 614,177, (lctoher 5, 1956. This applicationNovember 18, 1957, Serial No. 697,271

13 Claims. (Cl. 313-228) The invention relates generally to metalcutting tools and more particularly to an improved construction ofportable, hand held sheet metal cutting tools of the nibbler type, thisapplication being a continuation of copending application Serial No.614,177 now abandoned, filed October 5, 1956.

A principal object of the present invention is to provide such a toolwhich can be selectively arranged for movement in cutting direction withits main body .extending parallel to the work and normal to the line ofthe cut or optionally parallel to said line.

Another principal object of the present invention is to provide such atool which may be moved in cutting direction with its main bodyextending parallel to the work and normal to the line of the cut, andwhich may be rocked simultaneously back and forth about the longitudinalaxis of said main body when said line extends across corrugations formedin the work.

Other objects and advantages of the present invention will appear morefully hereinafter, it being understood that the invention consistssubstantially in the construction, combination, location and relativearrangement of parts, all as described in the accompanying drawings andas finally pointed out in the appended claims.

In the accompanying drawings:

Figure l is a perspective view of a tool constructed in accordance withand embodying the principles of the present invention, which tool isshown in the process of cutting a corrugated sheet of material;

Figure 2 is a view looking at one side of the fore end part of the tool,a portion being in elevation and a portion in vertical section;

Figure 3 is sectionon line 3 3 of Figure 2;

Figure 4 is front view of the tool, various positions thereof beingshown in broken lines;

Figure 5 is similar to Figure 2, but shows a different arrangement ofthe tool;

Figure 6 is a section on line 6 6 of Figure 2;

Figure 7 is a section on line 7-7 of Figure 5;

Figure 8 is a perspective view of the punch, shown'detached from therest of the tool;

Figure 9 is an exploded view of the fore end part of the tool, portionsbeing broken away and sectioned for the sake of clarity;

Figures 10 and 1l are sections respectively on lines 10-10 and 11-11 ofFigure 9;

Figure l2 is a view on line 12-12 of Figure 9;

Figure 13 is a section on line 13-13 of Figure 9;

Figure 14 is a View on line 14-14 of Figure 9;

Figure 15 is a plan view of the die member, shown alone; and

Figure 16 is a section on line 16-16 of Figure 15.

Referring to the drawings, the nibbler tool constructed in accordancewith and embodying the principles of the present invention includes ahousing that has an elongated main body 10 in which is encased anelectric motor (not shown). The latter is supplied with power throughthe medium of a cable 11, and this power is controlled through fingerpressure applied to a switch control lever 12. Suitably journalled inthe housing main body 10 is a shaft 13 that is operatively connected toand driven by the electric motor aforesaid and which has an eccentricfore end portion 14 extending freely into a head section 15 of thehousing.

Carried by the housing head section 15 is a vertically extending guidemember 16 that is round and tubular throughout the major portion of itslength, terminating in a more or less solid lower end or nose portion.Intermediate the opposite ends of the guide member 16 is acircumferentially extending ange 17 by means of which the guide memberis bolted, as by bolts 18, to the housing head section 15 with the upperend portion thereof ex-v tending freely well up into the head section15. On one side of the nose of the guide member, designated by thenumeral 19, is a T-shaped recess 20 that snugly receives thecorrespondingly shaped head of a die support member designated generallyby the numeral 21, which head, designated by the numeral 22 isdetachably secured to the nose 19, as by bolts 23.

The die support member 21 is provided with a punch backing part 24 thatextends downwardly in Vertical continuation of the head 22 aforesaid andhorizontally rearwardly from the back of a punch 25, to be describedhereinafter. Integral with the lower end portion of the punch backingpart 24 is a die mounting part that is in the form of a pair of arms26-26 which extend laterally outwardly on opposite sides of the punchbacking part 24 and forwardly therefrom.

Carried by the die support member 21 is a die member 27 that isrecessed, as at 28, to provide a pair of laterally spaced arms 29-29which are connected together by a fore end portion 30. This die memberis mounted withL the arms 29-29 thereof respectively overlying the arms26-26 aforesaid, and with the arm connecting portion 30 bridging the gapbetween the latter and disposed in spaced relation to the punch backingpart 24, in consequence of which the die member 27 and the punch backingpart 24 conjointly form a vertically extending open channel 31therebetween. The die member 27 is removably secured to the die mountingpart, as by bolts designated 32, and the arms 29-29 thereof are providedwith depending elements 33-33 each of which hooks over the rear endportion of the associated die mounting arm 26.

Slidably fitted into the guide member 16 is a ram 34 one side of whichis suitably recessed, as at 35, for operatively receiving the roundedlower end portion of a link 36. The upper end portion of the latter isconnected to the eccentric fore end portion 14 ofthe drive shaft 13. Theram 34 is bored to provide a central channel 3'7, and the nose 19 of theguide member 16 is bored to provide a channel 38, these channels 37 and38 being longitudinally aligned with one another and with the channel 31formed conjointly by the die member 27 and the punch backing part 24.The punch 25 is slidably fitted into the channel 37 and secured thereinby a pair of set screws 319-39. The nose 19 of the guide member is alsobored, as at 4il, for mounting a stripper member 4l that is secured inplace by a set screw 42. Y

Referring particularly to Figure 8, the punch 25 is a round bar sectionthe lower end portion of which is flattened on diametrically oppositesides, as at. 43-43, to form a comparatively thin blade 44, and theupper end portion of which is attened on two sides disposed at degreesto one another, as at 45-45, to form a comparatively heavy shank 46. Nowreferring to Figures 5 and 7, it will be observed that the punch 25 maybe turned about its longitudinal axis and positioned with the blade 44thereof normal to the plane aforesaid, with the set screws 39-39engaging the other flat surface 45 of the shank 46. Of course,repositioning the punch 25 in the manner just indicated, necessitates acorresponding change in the position of the die support member 21, diemember 27 and stripper member 41, which change is effected by suitablyreorienting the guide member 16 from which the members 21, 27 and 41aforesaid depend. The link 36 is of a thickness greater than the depthof the recess 35 into which it is fitted, in consequence of which theback of the link 36 is positioned outwardly beyond the outer surface ofthe ram, thereby forming an obstruction to turning of the guide member16 about the ram 34 for reorientation thereof. To avoid this obstructiona wall area is cut out of the guide member, which wall area, designatedby the numeral 47, extends from the top of the guide member 16downwardly to apoint just below the link 36 and circumferentiallythrough an arc of approximately 180 degrees.

The top or work supporting surface of the die member 27 is of convexshape, being curved, as at 48, in the direction of its length and beingat in the direction of its width.

' The punch backing part 24 is of an overall thickness which does notexceed the width of the punch blade 44. In horizontal section, justabove the die member 27, the punch backing part 24 is of wedge shape,the base of the wedge being proximate the punch blade 44 and the apex ofthe wedge being remote from the punch. This wedge shaped portion of thepunch backing part 24 increases in vertical extent from the proximity ofthe punch blade 44 outwardly therefrom, whereby to form a pair ofinclined shoulders, designated by the numeral 49, respectively disposedon opposite sides of the punch backing part.

The stripper member 41 is provided with a foot 50 that extends laterallyfrom a vertically adjustable shank and engages the punch blade 44, theunder surface of the foot being inclined, as at 51. Referringparticularly to Figures l and 4, to cut across the corrugations of acorrugated sheet of material, designated A, the tool is held parallel tothe work with the main body thereof extending normal to the line of thedesired cut, and a marginal area of the sheet at the point of entry ofthe tool is supported on the die member 27, adjacent the punch blade 44.Rotary motion of the drive shaft 13 is translated into reciprocatingmotion of the link 36, ram 34 and punch 25. As the latter nibblesthrough the material, the cut, designated B, is formed and the toolenters the work with the punch backing part 24 of the die support membertrailing the punch blade 44 and passing freely between the severedsections of the material. The tool is moved in the position aforesaidbut simultaneously is rocked by the operator about the longitudinal axisof its main body in order to keep the punch 25 as nearly as possiblenormal to the area of the work immediately underlying the punch.Referring particularly to Figure 4, in each position of the toolillustrated, the area of the work immediately underlying the punch 25 isfirmly seated upon the die member 27. When the tool is cutting along theside of a corrugation, the inclined shoulders 49-49 formed respectivelyas opposite sides of the punch backing part 24 clear the opposedcorrugation side, and when the tool is cutting between two eorrugations,these shoulders 49-49 clear one of the corrugation sides and theinclined under surface 51 of the stripper foot 50 clears the othercorrugation side.

To convert the tool for cutting while held in the conventional manner,parallel to the work and with the main body thereof extending parallelto the line of the cut,

rst the guide member 16 is detached from the housing i head section byremoving the bolts 18 and separating the guide member 16 and die supportmember 21, die member 27 and stripper member 41 as a unit from the ram34. Then the ram 34 is detached from the link 36, and the ram 34 andpunch 25 are removed from the Y 4 housing head section 15 as a unit.Next the set screws 39-39 are loosened, and the punch is given a quarterturn, whereupon the set screws 39--39 are retightened, and the ram 34and punch v25 are reattached as a unit to the link 36. Finally the guidemember 16 and die support member 21, die member 27 and stripper member41 are reattached to the housing head section 15 as a unit in acorrespondingly reoriented position.

The tool of the present invention can be utilized for cutting along astraight line or a curved line on either at or corrugated sheet materialirrespective of which of the illustrated arrangements is utilized.However, the arrangement of Figures 1 through 4 is particularly ad;vantageous because the main body of the tool is conveniently rockedabout its longitudinal axis when cutting across the corrugations of acorrugated sheet of material, instead of being tilted fore and aft,which tilting movement would materially limit the usefulness of thetool.

It will be understood, of course, that the present invention ashereinbefore described and as shown in the accompanying drawings issusceptible of various changes and modifications which may be made fromtime to time without departing from the general principles or realspirit of the invention, and accordingly it is intended to claim thesame broadly, as well as specifically, as indicated by the appendedclaims.

What is claimed as new and useful is:

l. A motor-driven sheet metal cutting tool comprising an elongated motorhousing adapted to be held by the operator over and parallel to ahorizontally extending sheet to be cut, a vertically extending guidemember provided in the fore end of said housing, a reciprocable ram ttedin said guide member, means intervening said motor drive and ram forreciprocating the latter, a die support member including a die mountingpart underlying and in spaced relation to said guide member, and a punchbacking part extending vertically between said die mounting part andguide member, a die member mounted upon said die mounting part andconjointly forming with said punch backing part a channel longitudinallyaligned with a channel formed in said ram, and a punch iixedly securedin said ram channel and reciprocable in the other of said channels, saiddie member being provided with an upper work supporting surface that isflat in a direction normal, and curved in a direction parallel, to theline of the cut to be made, the areas of said surface disposedrespectively fore and aft of said punch being adapted to drop verticallyaway from the work,l increasingly from the immediate proximity of thepunch outwardly inopposite directions, and being smoothly merged in theimmediate proximity of the punch.

2. A motor-driven sheet metal cutting tool as defined in claim l whereina portion of the punch backing part is of a vertical extent thatincreases from the punch'outwardly from the latter and is wedge shapedin horizontal section.

. 3. A motor-driven sheet metal cutting tool as dened in claim 1 whereinthe guide member carries a vertically extending stripper member having alateral extension that slidably supportingly engages the punch, saidstripper member is vertically adjustable relative to said guide member,and the under surface of said extention is sloped upwardly in cuttingdirection from the immediate proximity of the punch.

4. A motor-driven sheet metal cutting tool as dened in claim 1 wherein aportion of the punch backing part of a vertical extent that increasesfrom the punch out wardly from the latter is wedge shaped in horizontalsec tion to thereby form a shoulder that slopes upwardly from the punchin a direction opposite to cutting direction, and the guide membercarries a positionally adjustable vertically extending stripper memberthe under surface of which is sloped upwardly from the punch in cuttingdirection.

5. In a sheet metal punch, an elongated member made of bar stockuniformly round in transverse section including a shank portion at oneend and a blade portion at the opposite end, said shank portion beinguniform in transverse section and provided with a pair of longitudinallyextending sides flat and normal to one another, and a longitudinallyextending side rounded through a distance at least half-way about saidshank, and said blade portion being uniform in transverse section andprovided with a pair of longitudinally extending oppositely facing sidesat and parallel to one another, and a pair of longitudinally extendingoppositely facing rounded sides, the surface of each rounded sideaforesaid being an area of the outer surface of the round bar member ofwhich the punch is made.

6. In a sheet metal punch as defined in claim wherein diametricallyopposite the rounded shank side and intervening the pair of iiat shanksides is a fourth longitudinally extending rounded side that is an areaof the outer surface of the rounded bar member of which the punch ismade, and the blade portion is comparatively thin and at and disposed ina plane normal to one of said at shank sides.

7. In a motor-driven sheet metal cutting tool comprising a reciprocableram, a punch reciprocable with said ram and having a flat bladeextending from said ram in longitudinal continuation thereof, and a diemember adapted for reciprocation of said blade therein and having a worksupporting surface flat in the direction of the width of said blade andconvex in the direction of the thickness of Isaid blade, said die memberand punch being positionable together relative to said ram optionally ina plurality of different positions spaced angularly about thelongitudinal axis of said ram and said punch being detachably securableto said ram in any one of the different positions aforesaid.

8. In a motor-driven sheet metal cutting tool comprising a reciprocableram, a punch reciprocable with said ram and having a at blade extendingfrom said ram in longitudinal continuation thereof, a die member havinga work supporting surface at in the direction of the width of said bladeand convex in the 'direction of the thickness of said blade, avertically extending positionally adjustable stripper member on one sideof said blade having an undersurface sloped outwardly 4from said bladeand toward said ram, a punch backing part on the opposite side of saidblade, said blade being reciprocable between said stripper and diemembers `on the one side and said punch backing part on the oppositeside, said die and stripper members and punch and punch backing partbeing positionable together relative to said ram optionally in aplurality of different positions spaced angularly about the longitudinalaxis of said ram, and said punch being detachably securable to said ramin any one of the different positions aforesaid.

9. In a sheet metal punch, an elongated member made of bar stockuniformly round in transverse section including a shank portion at oneend and a blade portion at the opposite end, said shank portion beinguniform in transverse section and provided with a pair of longitudinallyextending sides at and normal to one another, and a longitudinallyextending side rounded through a distance at least half-way about saidshank.

10. In a sheet metal punch as defined in claim 9 wherein diametricallyopposite the rounded shank lside and intervening the pair of flat shanksides is a fourth longitudinally extending rounded side that is an areaof the outer surface of the rounded bar member of which the punch ismade.

11. A motor-driven sheet metal cutting tool comprising a motor housing,a reciprocable punch, and work support means including a part carried bysaid housing and extending therefrom along the back of said punch, and asecond part carried by said punch backing part and extending about andproviding a guide for the working end of said punch, said punch backingpart being provided with a wedge shaped portion extending axially ofsaid punch and disposed with the broad base surface thereof against theback of said punch, said wedge shaped portion being of increasing lengthfrom the back of said punch outwardly from the latter, whereby toprovide a pair of overhanging shoulders disposed respectively onopposite sides thereof and sloped axially of said punch from the back ofthe latter outwardly from the same and away from said second part of thework support means.

12. A motor-driven sheet metal cutting tool comprising a motor housing,a reciprocable punch, and work support means including a part carried bysaid housing and extending therefrom along the back of said punch, andasecond part carried by said punch backing part and extending about andproviding a guide for the working end of said punch, said punch backingpart being provided with a portion of substantially uniform thicknessundercut to provide a pair of shoulders respectively upon opposite sidesthereof sloped axially of said punch to provide a ared work dischargepassage underlying said shoulders.

13. A motor-driven sheet metal cutting tool comprising a motor housing,a reciprocable punch, and work support means including a part carried bysaid housing and extending therefrom along the back of said punch, and asecond part carried by said punch backing part and extending about andproviding a guide for the working end of said punch, said punch backingpart being provided with a portion of substantially uniform thicknessundercut to provide a pair of shoulders respectively upon opposite sidesthereof sloped in a direction parallel to the `cut to be made, and astripper member selectively shiftable axially of said punch and havingan undersurface sloped in a direction parallel to the cut to be made andaway from said convex work supporting surface, said under surface of thestripper and said work support surface conjointly affording a flaredentrance passage for the work, and said shoulders of the punch backingpart and said work support surface conjointly yaffording a flared workdischarge passage.

References Cited in the iile of this patent UNITED STATES PATENTS2,201,599 Trautmann May 21, 1940 2,217,393 Webb Oct. 8, 1940 2,272,295Forss Feb. 10, 1942 2,535,631 Gray Dec. 26, 1950 2,567,095 BenjaminSept. 4, 1951 2,632,950 Hedstrom Mar. 31, 1953 2,680,292 Kaufmann .Tune8, 1954 2,750,667 Johnson June 19, 1956

